Heat exchangers



F. A. DISINGER Erm. 2,988,335

HEAT EXCHANGERS June 13, 1961 2 Sheets-Sheet 1 Filed March 6, 1958 Pffunnmmnmmn r .iinmF-H* um AVAVAVAVAVA'A'AVA'A'AVAVAVAVAVAVAVAVAVl"r "uw fJune 13, 1961 F. A. DlslNGER ETAL 2,988,335

HEAT EXCHANGERS Filed March 6, 1958 2 Sheets-Sheet 2 A 7' TORNEY UnitedStates Patent() 2,988,335 i HEAT EXCHANGERS Frank A. Disinger, Lockport,and Vincenzo A. Nicola,

Middleport, N.Y., assignors to General Motors Corporation, Detroit,Mich., a corporation of Delaware `Filed Mar. 6, 1958, Ser. No. 719,639 2Claims. (Cl. 257-236) This invention relates to `heat exchangers andmore particularly to heat exchangers in which differential expansion ofthe metal parts is a problem due to special uses or high temperatures towhich the exchangers are subjected in conveying heat from one fluid toanother.

In many uses such as transferring heat from liquid metal to air, forexample, a problem has arisen to provide ample surfaces for counterflowheat exchange between the two fluids and, at the same time, to avoid anyundue variation in temperatures of the exchanger parts which would causefailures of those parts.` `If the exchanger casing and tubes are notsuch as to accommodate themselves as fully as possible to the expansionobtaining, metal fatigue will appear in localized and vital areas. Ifthe heat exchange surfaces are increased by the expedient of usingsmaller tubes, the danger of tube blockage increases and such anincrease, in turn, gives rise to a more adverse situation insofar as anyunbalanced expansion problem existing is concerned.

An object of the present invention is to provide an improved heatexchanger minimizing the adverse effects or stresses set up in the heatexchanger structure because of temperature differentials. Another objectis to provide a heat exchanger suitable for metal to air service undercounterflow conditions and in which eifective heat transfer areas arelarge in extent and in which small ow passages are avoided.

A feature of the present invention is a heat exchanger utilizing tubesand having a casing enclosing the tubes and being characterized byperipheral slots therein to accommodate liuid llow, the slots lying inplanes transverse to the tubes. Another feature is a heat exchanger witha casing substantially divided but not severed into portions byperipheral slots formed in the casing, the adjacent portions of thecasing being connected by an intake or diaphragm manifold capable offunctioning as such enclosing the slots.

These and other important features of the invention Will now bedescribed in detail in the specification and then pointed out moreparticularly in the appended claims.

In the drawings:

FIG. 1 is a sectional view through a heat exchanger with arrowsdepicting the counterflow paths of fluids;

FIG. 2 is a sectional View looking in the direction of the arrows 2-2 inFIG. l showing a portion of the heat exchanger and drawn to an enlargedscale;

FIG. 3 is a sectional view looking in the direction of the arrows 3-3 inFIG. l; and

FIG. 4 is a sectional view looking in the direction of the arrows 4-4 inFIG. l.

In the drawings, a heat exchanger is depicted having a casing generallyindicated at 10. This casing is cylindrical and comprises anintermediate portion 12 which is integral with two end portions 14 and16. IThe portion 14 bears a flange 18 by means of which it may beconnected to a source of supply for air. The end portion 16 is providedwith an end ange 20 which may be connected to a device for receiving airwhich has been heated in passing through the casing 10.

The end portion 14 is connected to the intermediate portion 12 by meansof casing sections 22 and 24. These sections are clearly seen in FIGS. 3and 4. It will be noted that the sections 22 lie in one plane transverseice to tubes 26 arranged within the casing 10 and that these sectionsserve to separate peripheral slots 28 and 30 which are formed in thecasing Iand in that same transverse plane. The sections 24 separate twoadditional slots 32 and 34 formed in the casing. The sections 22 alsomay be said to lie in a horizontal plane whereas the sections 24 lie ina vertical plane, and these planes extend parallel with the tubelengths. It will also be noted that the slots 28 and 30 lie in a planeparallel with the plane in which the slots 32 and 34 `lie and that thesections 22 are oifset an angle of 90 `from the sections 24 asconsidered in the direction of the casing axis.

An annular manifold 38 is provided in. the form of an inwardly directedtrough and it surrounds the casing 10 and joins the end portion 14 tothe intermediate portion 12 thereby enclosing the slots 28, 30, 32 and34. The manifold is joined to the intermediate portion 12 by welding asat 40 and to the end portion 14 as at 42. One end of a discharge conduit44 is joined to the manifold 38 by welding as at 46 and communicateswith the manifold.

The intermediate portion 12 of the casing is joined to the end portion16 by four olfset casing sections as determined by slots, these sectionsIbeing similar to the sections 22 and 24. Ioinder to the portion 12 isalso by an annular manifold 48 constructed in the same manner as themanifold 38. The manifold 48 is provided with an inlet conduit 50.

A circular tube sheet 51 is joined at its periphery to the end portion14 of the casing as by welding shown at 52. A similar tube sheet 54 isjoined in a similar manner to the end portion 16 of the casing.Communication is had between the two end portions 14 and 16 through theintermediate portion 12 by means of the tubes 26, the ends of which arexed to the tube sheets by conventional methods to form uid tight joints.

As seen in FIGS. 3 and 4, each tube is of elongated cross section thusforming a relatively large uid passageway through the full length of thetube, and in order to increase the heat capacity of the heat exchanger,each tube is fitted with an internal iin 60 of thin corrugated metalwhich extends the full length and width of that tube. Preferably, butnot necessarily, the corrugations in the ns are made to extendlengthwise of the tubes as shown in the drawings. Such tins could beslotted and take any of various forms suitable for transferring heat.

In operation of the heat exchanger, liqjuid metal ows from the conduit50 into the manifold 48. Prom this manifold it enters the chamber orintermediate portion 12 of the casing by way of the slots enclosed bythat manifold. This liquid metal circulates around the tubes 26 andflows to the left, as viewed in FIG. l, for discharge from the heatexchanger by Way of the slots 28, 30, 32 and 34 to the manifold 38 andfrom thence by way of the discharge conduit 44.

Air entering the casing end portion 14 at the left-hand opening thereof,-as viewed in FIG. l, passes through the tubes 26 in contact with thefins 60 and is discharged by way of the opening formed by the endportion 16. The counterow passage of the molten metal and air along thelengths of the tubes 26 effects efficient heat exchange. Forconvenience, the lair may be termed a first iluid and the molten metalmay be called the second fluid.

It is obvious from the above description that the physical integrity ofthe casing 10 is maintained by the casing sections separating ordetermined by the slots; and, despite such integrity, ample provision isprovided for minimizing the expansion problems due to possibletemperature variations in the casing and tubes.

It is also to be noted that the passages between the tubes 26 are ofsuch large cross section that any partial or localized blockage bymolten metal is not probable and, therefore, the possibility of unduetemperature diierentials in the metal parts of the exchanger isminimized. Since the casing 10 is not completely severed into portionsas is usually true when providing an expansion joint, fabrication of theexchanger is simplilied because additional xtures lare not required Vtoassure proper alignment of parts. With the use of two manifolds 38 and48, las depicted, each manifold may be relied upon to absorb one-half ofthe differential expansion involved and it also supplies the means for360 liquid metal distribution to the core or discharge from the core.

We claim:

1. A heat exchanger comprising a tubular casing having -inlet and outletopenings at each end for conducting a lirst lfluid, axially spacedtransverse tube sheets in the casing defining together with a portion ofthe casing a chamber for a second uid, tubes supported by said -tubesheets and extending through said chamber for conducting the first iluidbetween said openings, peripheral slots defining llow passages for thesecond fluid formed in the casing wall at each end of said chamber, saidslots being arranged in multiple parallel planes transverse to saidtubes and separated in each of said parallel planes by remaining casingwall sections, the said sections in said planes being relatively offsetin the direction of the casing axis, a manifold in the nature of anexpansion joint at each end of said chamber simultaneously serving as aconduit for the second fluid joined to the casing and straddling theslots to provide communication therewith and said chamber and an inletport for the second lluid in one manifold and an outlet port therefor inthe other.

2. A heat exchanger comprising means for accommodating ow of a firstduid in heat exchange relation with a second uid, said means including acasing having van intermediate portion and two end portions includinginlet and outlet for conducting said rst fluid, said portions beingjoined by casing sections separated by peripheral slots formed throughthe wall of said casing in at least two planes transverse to the casingaxis, a transverse tube sheet in each of said end portions, tubes.extending -through said intermediate portion and supported by 4saidtube sheets for conducting the `lirst Huid, the casing sections joiningeach of said end portions to said intermediate portion being offset inthe direction of the axis of the casing, said intermediate portion withsaid slots as ow passages serving to conduct the second fluid, amanifold in the nature of an expansion joint joining each end portion tosaid `intermediate portion, each of said manifolds straddling therespective slots -to form a uid passage around said casing incommunication with the slots and intermediate portion and an inlet portfor the Vsecond lluid in one manifold and an outlet port therefor in theother.

References Cited in the iile of this patent UNITED STATES PATENTSGermany Oct. 1,3, 1952

